Watch case



Dec. 5, 1967 M- JEANMONQD ET AL 3,355,875

WATCH CASE Filed Nov. 22, 1965 Arroz/var 3,355,875 WATCH CASE Maurice Jeanmonod, La Chaux-de-Fonds, Jean Pierre Dubois, Le Locle, and `lean-Claude Schneider, La Chaux-de-Fonds, Switzerland, assignors to Fabrique dhorlogerie Chs. 'Iissot et Fils S.A., Le Locle, Neuchtel, Switzerland, a company of Switzerland Filed Nov. 22, 1965, Ser. No. 508,935 Claims priority, application Switzerland, Dec. 22, 1964,

Claims. (Cl. 58-91) The present invention relates to a Watch case comprising a side wall of plastic material closed in itself, and a glass having a peripheral heel and removably secured to the said Wall by engagement of the heel at the inside of the wall.

A great number of different sol-utions have already been proposed for the fixation of the glass of a watch in the body of the case when the body is of plastic material. Since plastic material has a deformation capacity which is superior to that of metal, the methods of xation which are usual in connection with metallic Watch cases can generally not be applied when the body of the watch case is of plastic material. More particularly when it is desired to realize a Water-tight watch case it was heretofore necessary to resort to rather complicated devices comprising for example an independent metallic bezel screwed to the body of the watch case, and maintaining the glass in place.

The present invention aims to avoid these drawbacks of heretofore known watch c-ases provided with a watch case body of plastic material.

Another object of the invention is to realize a watertight watch in which the glass is secured to the case of plastic material by simple means.

To this end the watch case according to the present invention is characterized in that the inner face of the wall is provided with Ian annular groove housing a metallic ring closed in itself, said groove extending at such level that the heel of the glass is in contact with said ring when the glass is engaged in said wall.

The only figure of the accompanying drawing illustrates, by Way of example, a partial axial section through an embodiment of a watch case according to the present invention.

Referring to the drawing the illustrated watch case Icomprises a watch case body 1 of circular shape presenting an annular Wall 2 and which forms as well the bottom as the case band. This piece is destinated to receive a watch movement inserted from the top into the case and resting on an annular shoulder 3 of the watch body case 1. An opening (not shown) radially traversing the wall 2 affords for the securing to the body 1 of a tube for the passage of the winding stem of the movement.

The watch case body 1 is closed in its upper part by a glass 4 presenting at its periphery a heel 5, at the inner side of which is engaged a tensioning ring 6 ensuring the tightness of the joint between the glass and the body 1. The heel 5 is resilently engaged Within the wall 2. It presents a lateral outerface 7 of cylindrical shape which extends above of the upper rim of the wall 2, so that the glass 4 may be separated from the body 1 by means of a tool serrating the surface 7 and compressing it radially for disengagement.

The heel 5 is in contact with the upper face of an annular metallic element 8, constituted by a slotted ring the outer rim of which is engaged in a groove 9 provided in the inner cylindrical face of the wall 2. This ring 8 is undulated so as to present a certain resiliency in axial direction. It bears against the movement and ,United States Patent C) 3,355,875 Patented Dec. 5, 1967 maintains the latter axially in place while simultaneously ensuring the position of the glass in axial direction.

The case body 1 is manufactured by injection according to a known process. However, at the same moment of the injection, a circular ring 10 of rectangular crosssection is placed in the mould in such position that this ring is immerged in the upper part of the annular wall 2, its inner face being on a level with the inner face of said wall. This ring may, for example, be of steel, a material which presents a modulus of elasticity substantially superior to that of any of thermoplastic materials, such as nylon, that may be used for example to manufacture the case 1, or of the acrylic glass which constitutes the glass 4. It results therefrom that the heel of the glass is serrated by the ring 10, which solely supports the radial stresses exerted by the glass onto the case and which ensures a correct position and holding. The tensioning ring 6 thus aiiords for the realization of a water-tight watch case which, since the bottom and the case lband are of one piece, does not present any joint besides that between the tube and the winding stern. The latter may be rendered water-tight by well known usual means.

The described watch case may be realized as a pocket watch case or as a wrist-watch case. In the latter case the case body 1 would be provided with means for securing the wristlet, for example with horns.

The described arrangement could also be applied to a Watch case of non-circular shape, for example to a square or rectangular watch case. Of course the case body 1 could also be covered interior-ly or exteriorly with a metallic layer obtained by vaporisation or any other known process.

Instead of being of square or rectangular section the ring 10 couldalso be of trapezoidal or of any other sectional shape. Thus, or example, the inner face of the ring, instead of being cylindrical, could also be slightly truncated. The lateral outer face of the heel of the glass in such a case would have a shape corresponding to that of the inner face of the ring. Moreover, instead of extending on a level with the inner face of the wall 2, the inner face of the ring could also extend so as to slightly project inwardly with respect to the wall portion extending below this ring. This ring could then also form a retaining or hooking element for the glass heel, the lower rim of which instead of being chamfered, would then present a projecting lillet.

We claim:

1. In a watch case having a closed side wall and a transparent cover providing a peripheral flange tightly engaging said wall, said wall being composed of plastic material and having an inner surface containing an intermediately disposed Iannular groove, and a closed metallic annular ring received in said groove and engaging said flange.

2. In a watch case according to claim 1, said case being of circular shape, said metallic ring having a cylindrical inner face, said flange having a cylindrical outer lface, and said inner and outer faces contacting each other.

3. In a watch case according to claim 1, said metallic ring having an inner face lying flush with said side wall inner surface.

4. In a watch case according to claim 1 wherein said inner surface contains a second groove, and a resilient slotted ring removably engages said second groove and projects inwardly from said wall for engagement with said flange.

5. In a watch case according to claim 4 wherein the width of said second groove exceeds the thickness of the slotted ring and the latter is provided with undulations along its circumference.

6. In a Watch case according to claim 1 wherein a bottom wall of plastic material is integral with said side 'wall.

vand a bottom wall of plastic material integral with said "side wall denes a radially disposed annular shoulder "therewith for supporting a watch movement in cooperation with said slotted ring. V 9. In a watch case according to claim 8 wherein said ange has a rim portion in contact with said slotted ring.

tensioning ring is frictionally engaged at the interior of said ange and radially presses said ange against said metallic ring.

References Cited UNITED STATES PATENTS 3,959,911 11/1960 Piquerez 58--90 FOREIGN PATENTS 1,363,424 5/1964 France.

RICHARD B. WILKINSON, Primary Examiner.

GERALD F. BAKER, Examiner.

10. In a Watch case according to claim 8 wherein a 15 MICHAEL LORCH, Assistant Examiner. 

1. IN A WATCH CASE HAVING A CLOSED SIDE WALL AND A TRANSPARENT COVER PROVIDING A PERIPHERAL FLANGE TIGHTLY ENGAGING SAID WALL, SAID WALL BEING COMPOSED OF PLASTIC MATERIAL AND HAVING AN INNER SURFACE CONTAINING AN INTERMEDIATELY DISPOSED ANNULAR GROOVE, AND A CLOSED METALLIC ANNULAR RING RECEIVED IN SAID GROOVE AND ENGAGING SAID FLANGE. 